使用扭转谐振器装置对软组织粘弹性特性进行动态测量。

Dynamic measurement of soft tissue viscoelastic properties with a torsional resonator device.

作者信息

Valtorta Davide, Mazza Edoardo

机构信息

Swiss Federal Institute of Technology, Institute of Mechanical Systems, ETH Zentrum, 8092 Zurich, Switzerland.

出版信息

Med Image Anal. 2005 Oct;9(5):481-90. doi: 10.1016/j.media.2005.05.002.

DOI:10.1016/j.media.2005.05.002

PMID:16006169

Abstract

A new method for measuring the mechanical properties of soft biological tissues is presented. Dynamic testing is performed using a torsional resonator, whose free extremity is in contact with a tissue sample. An analytical model of a semi-infinite, homogenous, isotropic medium is used to model the shear wave propagation in the material sample and allows determining the complex shear modulus of the soft tissue. By controlling the vibration amplitude, shear strains of less than 0.2% are induced in the tissue so that the material response can be considered as linear viscoelastic. Experiments are performed at different eigenfrequencies of the torsional oscillator and the complex shear modulus is characterized in the range 1-10 kHz. In vitro experiments on bovine and porcine liver are presented in order to demonstrate the sensitivity of the proposed technique, and the reliability of the measurements is confirmed with comparative tests on synthetic material. The experiment does not damage the soft tissue and allows a fast and local measurement, these being prerequisites for future applications in vivo during open surgery.

摘要

提出了一种测量软生物组织力学性能的新方法。使用扭转谐振器进行动态测试，其自由端与组织样本接触。采用半无限、均匀、各向同性介质的解析模型来模拟材料样本中的剪切波传播，并确定软组织的复剪切模量。通过控制振动幅度，在组织中诱导出小于0.2%的剪切应变，从而使材料响应可被视为线性粘弹性。在扭转振荡器的不同本征频率下进行实验，并在1-10kHz范围内对复剪切模量进行表征。给出了对牛肝和猪肝的体外实验，以证明所提技术的灵敏度，并通过对合成材料的对比测试证实了测量的可靠性。该实验不会损伤软组织，且能进行快速局部测量，这些都是未来在开放手术中进行体内应用的先决条件。